Compression Examples
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The WorldWide Weather Workstation (W4) is a PC-based meteorological system that will deliver satellite images and forecast model data plus observational data to remote sites via satellite push technology or Internet where available. W4 utilizes a Linux PC platform that can receive a highly compressed stream of satellite broadcast data over modest bandwidths.
- Geostationary satellite data from all channels
- NWP model data from several different global forecast models (Tentatively the initial models used will be MRF and AVN)
- All internationally available observation data including
- Surface observations from manned and automated stations
- Aircraft reports
- Ship and buoy reports
- Upper air soundings
- The capability of adding local observation data available at a forecast office
The NOAA Forecast Systems Laboratory has developed a new workstation system called the WorldWide Weather Workstation (W4) which is based on the FSL developments for the AWIPS system. W4 is designed to meet the forecast needs of developing nations and to provide access to data for forecast situations where such data is currently unavailable. W4 can use a satellite broadcast, serving forecast needs within a continent or region-size footprint. It can also deliver satellite imagery and gridded model output via Internet to areas where connectivity is available. Both the server and the user subsystems utilize PC Linux platforms, substantially decreasing the system capital costs, while providing a high level of system performance.
Broadcast of weather data will be done using VSAT systems (Very Small Aperture Terminal) technology. The Forecast Systems Laboratory has done significant work on data compression techniques, particularly wavelet transform compression, that will allow a full set of forecast data to be transmitted over a 128 kbps satellite link. These data compression techniques will be applied to satellite imagery, observational data, and gridded Numerical Weather Prediction (NWP) model data sets. The significant improvement in efficiency of transmission will substantially decrease the operating costs for using the system.
W4 uses a series of scales, just as the AWIPS system does, that provide a display comparable to the size and type of the weather feature being studied. Important workstation features include overlay, animation, roam and zoom, predefined sets of procedures (sets of forecast products designed for a specific type of storm), family graphics, and toggle capabilities for displayed products.
The full resolution of the available data can be used in generating products at the user's workstation. Progressive disclosure is used to display a number of observations that are consistent with the scale. The W4 system was designed with consideration for low capital and operational costs, ease of installation, portability and flexibility.
W4 Applications:
W4 will benefit countries worldwide. Initially the focus is on making W4 available to forecasters in developing countries, (e.g., Central and South American countries). A further goal is for a national weather service in a representative country to participate in additional developments. This organization will assist in defining forecast products and procedures that fit its forecast needs. Later, the organization could serve as the initial test site and then as the first operational site for W4.
In addition to working with national weather services, W4 will be a valuable technology for emergency response users with a need to operate in remote locations such as for fire weather applications.
System Specifications:
W4 Client: Dual Pentium III 1 GHz processor, 512 MB RAM, Linux OS
W4 Server: Dual Pentium III 1 GHz processor, 512 MB RAM, Linux OS
Satellite Transmission: VSAT, 128 kbps
Contact: Sher Schranz
Telephone: 303-497-7254
email: Sher.Schranz@noaa.gov